The purpose of this proposal is to develop novel crystallization techniques applicable to membrane proteins in general. It is difficult to identify structural defects in membrane proteins which give rise to pathological states until an intimate knowledge of the structure of normal membrane proteins is attained. In this proposal two proteins, bacteriorhodopsin and rhodopsin which represent well-characterized model systems for membrane proteins and transport processes will be used for these crystallization studies. Crystallization will be investigated using delipidated bacteriorhodopsin and a variety of mutant forms of the protein which have been specifically developed, through recombinant DNA methods for structure function studies and to enhance the possibilities of producing high quality crystals. Special crystallization apparatuses which allow dynamic monitoring and control of the crystallization process have been constructed and will be used to optimize the crystallization conditions. The effects of newly synthesized surfactants with a broad range of hydrophilic groups, of the microgravity conditions present abroad the space shuttle and of important parameters such as temperature, pH, hv, and precipitant will also be investigated.